This invention relates to certain 4,5-disubstituted-2-aminopyrimidines, to processes for their preparation, to pharmaceutical compositions containing them, and to their use in medicine.
Angiogenesis, the growth of capillaries from existing blood vessels, is an essential process in normal embryonic development, tissue repair and some aspects of female reproductive function. It is also associated with the development of several pathological disorders including solid tumour growth, metastasis, psoriasis and rheumatoid arthritis, as well as diabetic retinopathy and age related macular degeneration (Folkman, Nature Medicine, (1995) 1, 27-310).
Several growth factors have been shown to mediate angiogenesis through alteration of vascular permeability, including vascular endothelial growth factor (VEGF; G. Breier et al., Trends in Cell Biology, 1996, 6, 454-6), platelet derived growth factor (PDGF) and acidic and basic fibroblast growth factors (a and b FGF).
VEGF in dimeric form is a ligand that binds to two transmembrane tyrosine kinase associated receptors, expressed exclusively on proliferating endothelial cells, KDR (Flk-1 in mice) also known as VEGFR-2, and Flt-1 also known as VEGFR-1. Binding of VEGF to KDR/Flk and Flt leads to receptor dimerisation, kinase activation, autophosphorylation of the receptor and phosphorylation of intracellular substrates. An analogous series of events ensues after ligand occupancy of the more widely expressed tyrosine kinase associated FGFr receptor by aFGF or bFGF. Thus receptor tyrosine kinase activity initiates a cellular signalling pathway leading to proliferation.
Antagonism of VEGF with antibody completely suppresses neovascularisation and growth of human rhabdomyosarcoma A673 speroids in athymic mice (Borgstrom et al, Cancer Res., 1996, 56 4032-4039). Suppression of bFGF gene expression by interferons xcex1 and xcex2 inhibits capillary density in mice, leading to pancreatic eyelet tumour suppression (Folkman et al, Proc. Natl. Acad.Sci. 1996, 93, 2002 and Singh et al Proc.Natl. Acad. Sci. 1995, 92, 10457). Other receptor associated kinases such as PDGFxcex2 and EGFr may also have some role in mediating angiogenesis.
We have now found certain 4,5-disubstituted-2-aminopyrimidines which are potent and selective inhibitors of receptor tyrosine kinases involved in angiogenesis, especially KDR kinase and/or FGFr kinase. Selective inhibition of these kinases can be expected to have a beneficial effect and the compounds are thus of use in the prophylaxis and treatment of disease states associated with angiogenesis, as described hereinafter.
Thus, according to one aspect of the invention, we provide a compound of formula (1): 
wherein
R1 is a xe2x80x94XR6 group [where X is a covalent bond, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94C(O)xe2x80x94, xe2x80x94C(S)xe2x80x94, xe2x80x94C(O)Oxe2x80x94, xe2x80x94S(O)xe2x80x94, xe2x80x94S(O2)xe2x80x94, xe2x80x94CH2xe2x80x94, or N(R7)xe2x80x94 [where R7 is a hydrogen atom or a straight or branched alkyl group] and R6 is a hydrogen or halogen atom or an optionally substituted aliphatic, cycloaliphatic, heteroaliphatic, heterocycloaliphatic, aromatic or heteroaromatic group, or a xe2x80x94NO2, xe2x80x94CN, xe2x80x94SO2N(R8)(R9) [where R8 and R9, which may be the same or different is a hydrogen atom or an optionally substituted aliphatic, cycloaliphatic, heteroaliphatic, heterocycloaliphatic, aromatic or heteroaromatic group], xe2x80x94CON(R8)(R9), xe2x80x94CSN(R8)(R9), xe2x80x94NH2 or substituted amino group;
R2 and R3 which may be the same or different is each a hydrogen or halogen atom or a group selected from an optionally substituted aliphatic, cycloaliphatic, heteroaliphatic, heterocycloaliphatic, xe2x80x94OH, xe2x80x94OR10 [where R10 is an optionally substituted aliphatic, cycloaliphatic, heteroaliphatic, heterocycloaliphatic, aromatic or heteroaromatic group] xe2x80x94SH, xe2x80x94NO2, xe2x80x94CN, xe2x80x94SR10, xe2x80x94COR10, S(O)R10, xe2x80x94SO2R8, xe2x80x94SO2N(R8)(R9), xe2x80x94CO2R8, xe2x80x94CON(R8)(R9), xe2x80x94CSN(R8)(R9), xe2x80x94NH2 or substituted amino group;
R4 is a X1R11 group where X1 is a covalent bond or a xe2x80x94C(R12)(R13)xe2x80x94 [where each of R12 and R13 is a hydrogen or halogen atom or a hydroxyl, alkyl or haloalkyl group] or xe2x80x94C(O)xe2x80x94 group and R11 is an optionally substituted phenyl, thienyl, thiazolyl or indolyl group;
R5 is a halogen atom or an alkynyl group;
and the salts, solvates, hydrates and N-oxides thereof.
In the compounds of formula (1), the term xe2x80x9coptionally substituted aliphatic groupxe2x80x9d when applied to each of the groups R2, R3, R6 and R10 means each of these groups may independently be for example an optionally substituted C1-10 aliphatic group, for example an optionally substituted straight or branched chain C1-6 alkyl, e.g. C1-3 alkyl, C2-6 alkenyl, e.g. C2-4 alkenyl, or C2-6 alkynyl, e.g. C2-4 alkynyl group. Each of said groups may be optionally interrupted by one or two heteroatoms or heteroatom-containing groups represented by X2 [where X2 is an xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atom or a xe2x80x94C(O)xe2x80x94, xe2x80x94C(S)xe2x80x94, xe2x80x94S(O)xe2x80x94, xe2x80x94S(O)2xe2x80x94, xe2x80x94N(R14)xe2x80x94 [where R14 is a hydrogen atom or a C1-6 alkyl, e.g. methyl or ethyl, group], xe2x80x94CON(R14)xe2x80x94, xe2x80x94OC(O)N(R14)xe2x80x94, xe2x80x94CSN(R14)xe2x80x94, xe2x80x94N(R14)COxe2x80x94, xe2x80x94N(R14)C(O)Oxe2x80x94, xe2x80x94N(R14)CSxe2x80x94, xe2x80x94SON(R14), xe2x80x94SO2N(R14), xe2x80x94N(R14)SO2xe2x80x94, xe2x80x94N(R14)CON(R14)xe2x80x94, xe2x80x94N(R14)CSN(R14)xe2x80x94, xe2x80x94N(R14)SON(R14)xe2x80x94 or xe2x80x94N(R14)SO2N(R14) group] to form an optionally substituted R2, R3, R6 and R10 heteroaliphatic group.
Particular examples of aliphatic groups represented by R2, R3, R6 and/or R10 include optionally substituted xe2x80x94CH3, xe2x80x94CH2CH3, xe2x80x94(CH2)2CH3, xe2x80x94CH(CH3)2, xe2x80x94(CH2)3CH3, xe2x80x94CH(CH3)CH2CH3, xe2x80x94CH2CH(CH3)2, xe2x80x94C(CH3)3, xe2x80x94(CH2)4CH3, xe2x80x94(CH2)5CH3, xe2x80x94CHCH2, xe2x80x94CHCHCH3, xe2x80x94CH2CHCH2, xe2x80x94CHCHCH2CH3, xe2x80x94CH2CHCHCH3, xe2x80x94(CH2)2CHCH2, xe2x80x94CCH, xe2x80x94CCCH3, xe2x80x94CH2CCH, xe2x80x94CCCH2CH3, xe2x80x94CH2CCCH3, or xe2x80x94(CH2)2CCH groups. Where appropriate each of said groups may be optionally interrupted by one or two atoms and/or groups X2 to form an optionally substituted heteroaliphatic group. Particular examples include xe2x80x94CH2X2CH3, xe2x80x94CH2X2CH2CH3, xe2x80x94(CH2)2X2CH3 and xe2x80x94(CH2)2X2CH2CH3 groups.
The optional substituents which may be present on these aliphatic and/or heteroaliphatic groups include one, two, three or more substituents selected from halogen atoms, e.g. fluorine, chlorine, bromine or iodine atoms, or hydroxyl, C1-6 alkoxy, e.g. methoxy or ethoxy, thiol, C1-6 alkylthio e.g. methylthio or ethylthio, xe2x80x94SC(NH)NH2, xe2x80x94CH2C(NH)NH2, amino, substituted amino, cyclic amino or heteroaromatic groups.
Substituted amino groups include for example groups of formulae xe2x80x94NR15R16 [where R15 is an optionally substituted C1-6 alkyl, C2-6alkenyl or C2-6alkynyl group optionally interrupted by one or two heteroatoms or heteroatom-containing groups represented by X3 (where X3 is an atom or group as described above for X2) and R16 is a hydrogen atom or is a group as just defined for R15], xe2x80x94N(R16)COR15, xe2x80x94N(R16)CSR15, xe2x80x94N(R16)SOR15, xe2x80x94N(R16)SO2R15, xe2x80x94N(R16)CONH2, xe2x80x94N(R16)CONR15R16, xe2x80x94N(R16)C(O)OR15, xe2x80x94N(R16)C(NH)NH2, xe2x80x94N(R16)C(NH)NR15R16, xe2x80x94N(R16)CSNH2, xe2x80x94N(R16)CSNR15R16, xe2x80x94N(R16)SONH2, xe2x80x94N(R16)SONR15R16, xe2x80x94N(R16)SO2NH2, xe2x80x94N(R16)SO2NR15R16, or xe2x80x94N(R16)Cyc1 [where Cyc1 is an optionally substituted C3-7 monocyclic carbocyclic group optionally containing one or more xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atoms or xe2x80x94N(R14)xe2x80x94, xe2x80x94C(O)xe2x80x94, xe2x80x94C(S)xe2x80x94, xe2x80x94S(O)xe2x80x94 or xe2x80x94S(O2)xe2x80x94 groups].
Cyclic amino substituents which may be present on R2, R3, R6 and/or R10 aliphatic or heteroaliphatic groups include groups of formula xe2x80x94NHet1, where xe2x80x94NHet1 is an optionally substituted C3-7 cyclic amino group optionally containing one or more other heteroatoms or heteroatom containing groups selected from xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atoms xe2x80x94N(R14)xe2x80x94, xe2x80x94C(O), xe2x80x94C(S)xe2x80x94, xe2x80x94S(O)xe2x80x94 or xe2x80x94S(O2)xe2x80x94 groups.
Particular examples of amino, substituted amino and cyclic amino groups include xe2x80x94NH2, methylamino, ethylamino, dimethylamino, diethylamino, xe2x80x94NHCyc1 where Cyc1 is an optionally substituted cyclopentyl, cyclohexyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl or thiomorpholinyl group, or xe2x80x94NHet1 where xe2x80x94NHet1 is an optionally substituted pyrrolidinyl, imidazolidinyl, pyrazolidinyl, piperidinyl, morpholinyl, piperazinyl or thiomorpholinyl group. Optional substituents which may be present on these groups and substituted and cyclic amino groups in general include one, two or three halogen atoms, e.g. fluorine, chlorine, bromine or iodine atoms, or C1-4alkyl, e.g. methyl or ethyl, hydroxyl, C1-4alkoxy, e.g. methoxy or ethoxy or pyridyl groups.
Optional heteroaromatic substituents which may be present on the aliphatic or heteroaliphatic groups represented by R2, R3, R6 and/or R10 include those heteroaromatic groups described below in relation to R2, R3, R6 and R10.
When R2, R3, R6 and/or R10 is present in compounds of formula (1) as an optionally substituted cycloaliphatic group it may be an optionally substituted C3-10 cycloaliphatic group. Particular examples include optionally substituted C3-10cycloalkyl, e.g. C3-7cycloalkyl, or C3-10cycloalkenyl e.g. C3-7cycloalkenyl groups.
Heteroaliphatic or heterocycloaliphatic groups represented by R2, R3, R6 and/or R10 include the aliphatic or cycloaliphatic groups just described for these substituents but with each group additionally containing one, two, three or four heteroatoms or heteroatom-containing groups represented by X2, where X2 is as described above.
Particular examples of R2, R3, R6 and/or R10 cycloaliphatic and heterocycloaliphatic groups include optionally substituted cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, 2-cyclobuten-1-yl, 2-cyclopenten-1-yl, 3-cyclopenten-1-yl, 2,4-cyclopentadien-1-yl, 3,5,-cyclohexadien-1-yl, tetrahydrofuranyl, pyrroline, e.g. 2- or 3-pyrrolinyl, pyrrolidinyl, dioxolanyl, e.g. 1,3-dioxolanyl, imidazolinyl, e.g. 2-imidazolinyl, imidazolidinyl, pyrazolinyl, e.g. 2-pyrazolinyl, pyrazolidinyl, pyranyl, e.g. 2- or 4-pyranyl, piperidinyl, 1,4-dioxanyl, morpholinyl, 1,4-dithianyl, thiomorpholinyl, piperazinyl, 1,3,5-trithianyl, oxazinyl, e.g. 2H-1,3-, 6H-1,3-, 6H-1,2-, 2H-1,2- or 4H-1,4-oxazinyl, 1,2,5-oxathiazinyl, isoxazinyl, oxathiazinyl, e.g. 1,2,5 or 1,2,6-oxathiazinyl, or 1,3,5-oxadiazinyl groups.
Optional substituents which may be present on R2, R3, R6 and/or R10 cycloaliphatic and heterocycloaliphatic groups include those optional substituents described above for R6 when it is an aliphatic group. The heterocycloaliphatic groups may be attached to the remainder of the molecule of formula (1) through any appropriate ring carbon or heteroatom.
When R2, R3, R6 and/or R10 is present as an aromatic group in compounds of formula (1) it may be for example an optionally substituted monocyclic or bicyclic fused ring C6-12 aromatic group, such as an optionally substituted phenyl, 1- or 2-naphthyl, 1- or 2-tetrahydronaphthyl, indanyl or indenyl group.
Heteroaromatic groups represented by R2, R3, R6 and/or R10 include optionally substituted C1-9 heteroaromatic groups containing for example one, two, three or four heteroatoms selected from oxygen, sulphur or nitrogen atoms. In general, the heteroaromatic groups may be for example monocyclic or bicyclic fused ring heteroaromatic groups. Monocyclic heteroaromatic groups include for example five- or six-membered heteroaromatic groups containing one, two, three or four heteroatoms selected from oxygen, sulphur or nitrogen atoms. Bicyclic heteroaromatic groups include for example nine- to thirteen-membered fused-ring heteroaromatic groups containing one, two or more heteroatoms selected from oxygen, sulphur or nitrogen atoms.
Examples of heteroaromatic groups represented by R2, R3, R6 and/or R10 include optionally substituted pyrrolyl, furyl, thienyl, imidazolyl, N-methylimidazolyl, N-ethyl-imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, 1,3,4-thiadiazole, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, benzofuryl, [2,3-dihydro]benzofuryl, isobenzofuryl, benzothienyl, benzotriazolyl, isobenzothienyl, indolyl, isoindolyl, benzimidazolyl, imidazo[1,2-a]pyridyl, benzothiazolyl, benzoxazolyl, benzopyranyl, [3,4-dihydro]benzopyranyl, quinazolinyl, naphthyridinyl, pyrido[3,4-b]pyridyl, pyrido[3,2-b]pyridyl, pyrido[4,3-b]pyridyl, quinolinyl, isoquinolinyl, tetrazolyl, 5,6,7,8-tetrahydroquinolinyl, 5,6,7,8-tetrahydroisoquinolinyl, and imidyl, e.g. succinimidyl, phthalimidyl, or naphthalimidyl such as 1,8-naphthalimidyl.
Optional substituents which may be present on any of the just described aromatic or heteroaromatic groups include one, two, three or more substituents, each represented by the group R17 as more particularly defined below in relation to the phenyl substituent R11.
Substituted amino groups represented by the groups R1, R2 and/or R3 in compounds of formula (1) include for example the groups xe2x80x94NR15R16, xe2x80x94N(R16)COR15, xe2x80x94N(R16)CSR15, xe2x80x94N(R16)SOR15, xe2x80x94N(R16)SO2R15, xe2x80x94N(R16)CONH2, xe2x80x94N(R16)CONR15R16, xe2x80x94N(R16)C(O)OR15, xe2x80x94N(R16)C(NH)NH2, xe2x80x94N(R16)C(NH)NR15R16, xe2x80x94N(R16)CSNH2, xe2x80x94N(R16)CSNR15R16, xe2x80x94N(R16)SONH2, xe2x80x94N(R16)SONR15R16, xe2x80x94N(R16)SO2NH2, xe2x80x94N(R16)SO2NR15R16, xe2x80x94N(R16)Cyc1 where R15, R16 and Cyc1 are as defined above.
Halogen atoms represented by the group R5 in compounds of the invention include fluorine, chlorine, bromine and iodine atoms. Alkynyl groups represented by R5 include xe2x80x94CCH and CCCH3 groups.
The group R11 in compounds of formula (1) may be a phenyl or substituted phenyl group. The substituted phenyl group may contain one, two, three or more substituents, each represented by the group R17.
The substituent R17 may be selected from an atom or group R18 or -Alk(R18)m, where R18 is a halogen atom, or an amino (xe2x80x94NH2), xe2x80x94NHR19 [where R19 is an -Alk(R18)m, heterocycloaliphatic, -Alk-heterocycloaliphatic, aryl or heteroaryl group], xe2x80x94N(R19)2 [where each R19 group is the same or different], nitro, cyano, hydroxyl (xe2x80x94OH), xe2x80x94OR19, formyl, carboxyl (xe2x80x94CO2H), esterified carboxyl, thiol (xe2x80x94SH), xe2x80x94SR19, xe2x80x94COR19, xe2x80x94CSR19, xe2x80x94SO3H, xe2x80x94SO2R19, xe2x80x94SO2NH2, xe2x80x94SO2NHR19, SO2N[R19]2, xe2x80x94CONH2, xe2x80x94CSNH2, xe2x80x94CONHR19, xe2x80x94CSNHR19, xe2x80x94CON[R19]2, xe2x80x94CSN[R19]2, xe2x80x94N(R14)SO2H [where R14 is as defined above], xe2x80x94N(R14)SO2R19, xe2x80x94N[SO2R19]2, xe2x80x94N(R14)SO2NH2, xe2x80x94N(R14)SO2NHR19, xe2x80x94N(R14)SO2N[R19]2, xe2x80x94N(R14)COR19, xe2x80x94N(R14)CONH2, xe2x80x94N(R14)CONHR19, xe2x80x94N(R14)CON[R19]2, xe2x80x94N(R14)CSR19, xe2x80x94N(R14)CSNH2, xe2x80x94N(R14)CSNHR19, xe2x80x94N(R14)CSN[R19]2, xe2x80x94N(R14)C(O)OR19, or an optionally substituted cycloaliphatic, heterocycloaliphatic, aryl or heteroaryl group; Alk is a straight or branched C1-6 alkylene, C2-6 alkenylene or C2-6 alkynylene chain, optionally interrupted by one, two or three xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atoms or S(O)xe2x80x94, xe2x80x94S(O)2xe2x80x94 or xe2x80x94N(R14)xe2x80x94 groups; and m is zero or an integer 1, 2 or 3.
When in the group -Alk(R18)m m is an integer 1, 2 or 3, it is to be understood that the substituent or substituents R18 may be present on any suitable carbon atom in -Alk. Where more than one R18 substituent is present these may be the same or different and may be present on the same or different atom in -Alk or in R17 as appropriate. Thus for example, R17 may represent a xe2x80x94CH(R18)2 group, such as a xe2x80x94CH(OH)Ar group where Ar is an aryl or heteroaryl group as defined below. Clearly, when m is zero and no substituent R18 is present the alkylene, alkenylene or alkynylene chain represented by Alk becomes an alkyl, alkenyl or alkynyl group.
When R18 is a halogen atom it may be for example a fluorine, chlorine, bromine, or iodine atom.
Esterified carboxyl groups represented by the group R18 include groups of formula xe2x80x94CO2Alk1 wherein Alk1 is a straight or branched, optionally substituted C1-8 alkyl group such as a methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl or t-butyl group; a C6-12arylC1-8alkyl group such as an optionally substituted benzyl, phenylethyl, phenylpropyl, 1-naphthylmethyl or 2-naphthylmethyl group; a C6-12aryl group such as an optionally substituted phenyl, 1-naphthyl or 2-naphthyl group; a C6-12aryloxyC1-8alkyl group such as an optionally substituted phenyloxymethyl, phenyloxyethyl, 1-naphthyloxymethyl, or 2-naphthyloxymethyl group; an optionally substituted C1-8alkanoyloxyC1-8alkyl group, such as a pivaloyloxymethyl, propionyloxyethyl or propionyloxypropyl group; or a C6-12aroyloxyC1-8alkyl group such as an optionally substituted benzoyloxyethyl or benzoyl-oxypropyl group. Optional substituents present on the Alk1 group include R18 substituents described above.
When Alk is present in or as a substituent R17 it may be for example a methylene, ethylene, n-propylene, i-propylene, n-butylene, i-butylene, s-butylene, t-butylene, ethenylene, 2-propenylene, 2-butenylene, 3-butenylene, ethynylene, 2-propynylene, 2-butynylene or 3-butynylene chain, optionally interrupted by one, two, or three xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94, atoms or xe2x80x94S(O)xe2x80x94, xe2x80x94S(O)2xe2x80x94 or xe2x80x94N(R14)xe2x80x94 groups.
When R18 is present in compounds of formula (1) as an optionally substituted cycloaliphatic group it may be an optionally substituted C3-10 cycloaliphatic group. Particular examples include optionally substituted C3-10cycloalkyl, e.g. C3-7cycloalkyl, or C3-10cycloalkenyl e.g. C3-7cycloalkenyl groups.
Heterocycloaliphatic groups represented by R19 and when present R19 include the cycloaliphatic groups just described for R18 but with each group additionally containing one, two, three or four heteroatoms or heteroatom-containing groups selected from xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atoms or xe2x80x94N(R14)xe2x80x94, xe2x80x94C(O), xe2x80x94C(S)xe2x80x94, xe2x80x94S(O)xe2x80x94 or xe2x80x94S(O2)xe2x80x94 groups.
Particular examples of R18 cycloaliphatic and R18 or R19 heterocycloaliphatic groups include optionally substituted cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, 2-cyclobuten-1-yl, 2-cyclopenten-1-yl, 3-cyclopenten-1-yl, 2,4-cyclopentadien-1-yl, 3,5,-cyclohexadien-1-yl, tetrahydrofuranyl, pyrroline, e.g. 2- or 3-pyrrolinyl, pyrrolidinyl, dioxolanyl, e.g. 1,3-dioxolanyl, imidazolinyl, e.g. 2-imidazolinyl, imidazolidinyl, pyrazolinyl, e.g. 2-pyrazolinyl, pyrazolidinyl, pyranyl, e.g. 2- or 4-pyranyl, piperidinyl, 1,4-dioxanyl, morpholinyl, 1,4-dithianyl, thiomorpholinyl, piperazinyl, 1,3,5-trithianyl, oxazinyl, e.g. 2H-1,3-, 6H-1,3-, 6H-1,2-, 2H-1,2- or 4H-1,4-oxazinyl, 1,2,5-oxathiazinyl, isoxazinyl, oxathiazinyl, e.g. 1,2,5 or 1,2,6-oxathiazinyl, or 1,3,5-oxadiazinyl groups.
Optional substituents which may be present on R18 cycloaliphatic and R18 or R19 heterocycloaliphatic groups include one, two, three or more substituents selected from halogen atoms, e.g. fluorine, chlorine, bromine or iodine atoms, or hydroxyl, C1-6alkoxy, e.g. methoxy or ethoxy, thiol, C1-6alkylthio, e.g. methylthio or ethylthio, hydroxy, C1-6alkyl, e.g. hydroxymethyl, hydroxyethyl, xe2x80x94CN, xe2x80x94NO2, xe2x80x94NHR14 or xe2x80x94N(R14)2 groups.
Aryl and heteroaryl groups represented by the group R18 or Ar include for example optionally substituted monocyclic or bicyclic C6-12 aromatic groups, e.g. phenyl groups, or C1-9 heteroaromatic groups such as those described above in relation to the group R6. Optional substituents which may be present on these groups include one, two or three R18a atoms or groups described below.
Particularly useful atoms or groups represented by R18, -Alk(R18)m or R18a as appropriate include fluorine, chlorine, bromine or iodine atoms, or C1-6alkyl, e.g. methyl or ethyl, C1-6alkylamino, e.g. methylamino or ethylamino, C1-6hydroxyalkyl, e.g. hydroxymethyl or hydroxyethyl, C1-6alkylthiol e.g. methylthiol or ethylthiol, C1-6alkoxy, e.g. methoxy or ethoxy, C5-7cycloalkoxy, e.g. cyclopentyloxy, haloC1-6alkyl, e.g. trifluoromethyl, C1-6alkylamino, e.g. methylamino or ethylamino, amino (xe2x80x94NH2), aminoC1-6alkyl, e.g. aminomethyl or aminoethyl, C1-6dialkylamino, e.g. dimethylamino or diethylamino, imido, such as phthalimido or naphthalimido, e.g. 1,8-naphthalimido, 1,1,3-trioxo-benzo[d]-thiazolidino, nitro, cyano, hydroxyl (xe2x80x94OH), formyl [HC(O)xe2x80x94], carboxyl (xe2x80x94CO2H), xe2x80x94CO2Alk1 [where Alk1 is as defined above], C1-6 alkanoyl e.g. acetyl, thiol (xe2x80x94SH), thioC1-6alkyl, e.g. thiomethyl or thioethyl, xe2x80x94SC(NH2+)NH2, sulphonyl (xe2x80x94SO3H), C1-6alkylsulphonyl, e.g. methylsulphonyl, aminosulphonyl (xe2x80x94SO2NH2), C1-6alkylaminosulphonyl, e.g. methylaminosulphonyl or ethylaminosulphonyl, C1-6dialkylaminosulphonyl, e.g. dimethylaminosulphonyl or diethylaminosulphonyl, phenylaminosulphonyl, carboxamido (xe2x80x94CONH2), C1-6alkylaminocarbonyl, e.g. methylaminocarbonyl or ethylaminocarbonyl, C1-6dialkylaminocarbonyl, e.g. dimethylaminocarbonyl or diethylaminocarbonyl, sulphonylamino (xe2x80x94NHSO2H), C1-6alkylsulphonylamino, e.g. methylsulphonylamino or ethylsulphonylamino, C1-6dialkylsulphonylamino, e.g. dimethylsulphonylamino or diethylsulphonylamino, optionally substituted phenylsulphonylamino, e.g. 2-, 3- or 4-substituted phenylsulphonylamino such as 2-nitrophenylsulphonylamino, aminosulphonylamino (xe2x80x94NHSO2NH2), C1-6alkylaminosulphonylamino, e.g. methylaminosulphonylamino or ethylaminosulphonylamino, C1-6dialkylaminosulphonylamino, e.g. dimethylaminosulphonylamino or diethylaminosulphonylamino, phenylaminosulphonylamino, aminocarbonylamino, C1-6alkylaminocarbonylamino e.g. methylaminocarbonylamino or ethylaminocarbonylamino, C1-6dialkylaminocarbonylamino, e.g. dimethylaminocarbonylamino or diethylaminocarbonylamino, phenylaminocarbonylamino, C1-6alkanoylamino, e.g. acetylamino, optionally substituted phenylcarbonylamino, C1-6alkanoylaminoC1-6alkyl, e.g. acetylaminomethyl, C1-6alkoxycarbonylamino, e.g. methoxycarbonylamino, ethoxycarbonylamino or t-butoxycarbonylamino, optionally substituted heteroC3-6cycloalkyl, e.g. piperidinyl, piperazinyl, 4-(C1-6alkyl)piperazinyl, e.g. 4-methylpiperazinyl, homopipeprazinyl, or morpholinyl, optionally substituted heteroC3-6cycloalkylC1-6alkyl, e.g. piperidinylC1-6alkyl, piperazinylC1-6alkyl, 4-(C1-6alkyl)piperazinylC1-6alkyl, e.g. 4-methylpiperazinylmethyl, or morpholinyl-C1-6alkyl, optionally substituted heteroC3-6alkylC1-6alkylamino, optionally substituted heteroC3-6cycloalkylamino, tetrazolyl, optionally substituted imidazolylC1-6alkyl, optionally substituted phenylamino, optionally substituted benzylamino, optionally substituted benzyloxy, or optionally substituted pyridylmethylamino group.
Where desired, two R18 or -Alk(R18)m or R18a substituents may be linked together to form a cyclic group such as a cyclic ether, e.g. a C2-6alkylenedioxy group such as ethylenedioxy.
It will be appreciated that where two or more R18, -Alk(R18)m or R18a substituents are present, these need not necessarily be the same atoms and/or groups.
Especially useful R18, -Alk(R18)m or R18a substituents include for example fluorine, chlorine, bromine or iodine atoms, or a methylamino, ethylamino, hydroxymethyl, hydroxyethyl, methylthiol, ethylthiol, methoxy, ethoxy, n-propoxy, 2-hydroxyethoxy, 3-hydroxypropoxy, 4-hydroxybutoxy, 2-amino-ethoxy, 3-aminopropoxy, 2-(methylamino)ethoxy, 2-(dimethylamino)ethoxy, 3-(dimethylamino)propoxy, cyclopentyloxy, cyclohexyl, cyclohexylamino, 2-hydroxycyclohexylamino, trifluoromethyl, trifluoromethoxy, methylamino, ethylamino, amino (xe2x80x94NH)2, aminomethyl, aminoethyl, dimethylamino, diethylamino, ethyl(methyl)amino, propyl(methyl)amino, 2-hydroxyethylamino, 3-hydroxypropylamino, 4-hydroxybutylamino, 2-aminoethylamino, 3-aminopropylamino, 4-aminobutylamino, 2-(methylamino)ethylamino, 2-(ethylamino)ethylamino, 2-(i-propylamino)ethylamino, 3-(i-propylamino)propylamino, 2-(dimethylamino)ethylamino, 3-(dimethylamino)propylamino, 2-(diethylamino)ethylamino, 3-(diethylamino)propylamino, 2-(methylamino)ethyl(methyl)amino, 3-(methylamino)propyl(methyl)amino, 2-(dimethylamino)ethyl(methyl)amino, 2-(dimethylamino)ethyl(ethyl)amino, nitro, cyano, hydroxyl (xe2x80x94OH), formyl [HC(O)xe2x80x94], carboxyl (xe2x80x94CO2H), xe2x80x94CH2CO2H, xe2x80x94OCH2CO2H, xe2x80x94CO2CH3, xe2x80x94CO2CH2CH3, xe2x80x94CH2CO2CH3, xe2x80x94CH2CO2CH2CH3, xe2x80x94CH2CO2CH2phenyl, t-butoxycarbonylmethoxy, acetyl, phenacetyl, thio (xe2x80x94SH), thiomethyl, thioethyl, xe2x80x94SC(NH)NH2, sulphonyl (xe2x80x94SO2H), methylsulphonyl, methylaminosulphonyl, ethylaminosulphonyl, dimethylaminosulphonyl, diethylaminosulphonyl, carboxamido (xe2x80x94CONH2), methylaminocarbonyl, ethylaminocarbonyl, dimethylaminocarbonyl, diethylaminocarbonyl, methylaminocarbonylmethyl, xe2x80x94NHC(S)NH2, sulphonylamino (xe2x80x94NHSO2H), methylsulphonylamino ethylsulphonylamino, dimethylsulphonylamino, diethylsulphonylamino, sulphonylamino (xe2x80x94NHSO2NH2), methylaminosulphonylamino, ethylaminosulphonylamino, dimethylaminosulphonylamino, diethylaminosulphonylamino, methylaminocarbonylamino, ethylaminocarbonylamino, dimethylaminocarbonylamino diethylaminocarbonylamino, acetylamino, phenylcarbonylamino, aminomethylcarbonylamino, acetylaminomethyl, methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, pyrrolidinyl, piperidinyl, piperazinyl, 4-methyl-piperazinyl, homopiperazinyl, morpholinyl, pyrrolidinylC1-6alkyl, piperidinylC1-6alkyl, piperazinylC1-6alkyl, 4-(C1-6alkyl)piperazinylC1-6akyl, morpholinylC1-6alkyl, 2-pyrrolidinylethylamino, 2-(1-methylpyrrolidinyl)-ethylamino, 1-ethylpyrrolidinylmethylamino, piperidinylamino, 1-benzylpiperidinylamino, imidazolylmethyl, imidazolylethyl, 4-(methoxy)phenylamino, 4-(3-hydroxypropyl)phenylamino, benzylamino, benzyloxy or pyridiylmethylamino group.
When X1 is present in compounds of the invention as a xe2x80x94(R12)(R13)xe2x80x94 group it may be for example a xe2x80x94CH2xe2x80x94 or xe2x80x94C(R12)(R13)xe2x80x94 group in which R12 and/or R13 is each a halogen atom such as a fluorine or chlorine atom or a hydroxy, C1-6alkyl e.g. methyl, ethyl or i-propyl, or C1-6haloalkyl, e.g. trihalomethyl such as a trifluoromethyl group. Particular examples of such xe2x80x94C(R12)(R13)xe2x80x94 groups include xe2x80x94CHFxe2x80x94, xe2x80x94CH(CH3)xe2x80x94, xe2x80x94C(OH)(CF3)xe2x80x94 and xe2x80x94CH(CF3)xe2x80x94 groups.
The presence of certain substituents in the compounds of formula (1) may enable salts of the compounds to be formed. Suitable salts include pharmaceutically acceptable salts, for example acid addition salts derived from inorganic or organic acids, and salts derived from inorganic and organic bases.
Acid addition salts include hydrochlorides, hydrobromides, hydroiodides, alkylsulphonates, e.g. methanesulphonates, ethanesulphonates, or isethionates, arylsulphonates, e.g. p-toluenesulphonates, besylates or napsylates, phosphates, sulphates, hydrogen sulphates, acetates, trifluoroacetates, propionates, citrates, maleates, fumarates, malonates, succinates, lactates, oxalates, tartrates and benzoates.
Salts derived from inorganic or organic bases include alkali metal salts such as sodium or potassium salts, alkaline earth metal salts such as magnesium or calcium salts, and organic amine salts such as morpholine, piperidine, piperazine, dimethylamine or diethylamine salts.
Particularly useful salts of compounds according to the invention include pharmaceutically acceptable salts, especially acid addition pharmaceutically acceptable salts.
It will be appreciated that depending on the nature of the substituents R1, R2, R3 and R4 the compounds of formula (1) may exist as tautomers and/or geometrical isomers and/or may have one or more chiral centres so that enantiomers or diasteromers may exist. It is to be understood that the invention extends to all such tautomers and isomers of the compounds of formula (1), and to mixtures thereof, including racemates.
In the compounds according to the invention the group R4 is preferably a group X1R11 in which X1 is a covalent bond.
The group R5 in compounds of the invention is in particular a bromine or, especially a chlorine atom.
A particularly useful group of compounds according to the invention has the formula (1a): 
wherein R1, R2, R3, R4 and R5 are as defined for formula (1).
One particular class of compounds of formulae (1) and (1a) is that wherein one or both of R2 and R3 is a hydrogen atom. Compounds in which R2 and R3 is each a hydrogen atom are especially useful.
In compounds of this class R1 is in particular a group -(Alk2)pNH2 (where Alk2 is as defined above for Alk and p is zero or an integer 1), -(Alk2)pNR15R16 (where R15 and R16 are as defined above), -(Alk2)pNHet2 (where xe2x80x94NHet2 is as defined above for NHet1), -(Alk2)pOH, and -(Alk2)pAr (where Ar is a nitrogen-containing heteroaromatic group as defined above). Especially useful R1 substituents include -Alk2NH2, particularly xe2x80x94(CH2)2NH2 and xe2x80x94C(CH3)2NH2, -Alk2NR15R16, particularly xe2x80x94CH2N(CH2CH3)2 and xe2x80x94(CH2)2NHC(CH3)3, -(Alk)2pNHet2 where xe2x80x94NHet2 is an optionally substituted pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl or thiomorpholinyl group, -Alk2OH, particularly xe2x80x94(CH2)2OH and -(Alk2)pAr where Ar is an optionally substituted imidazolyl or benzimidazolyl group. Optional substituents which may be present on these particular xe2x80x94NHet2 or
Ar groups include those generally and particularly described above in relation to the groups xe2x80x94NHet1 and Ar.
In general in compounds of formulae (1) or (1a) R4 is preferably a group X1R11 in which X1 is a covalent bond and R11 is a phenyl or, especially, a substituted phenyl group containing one, two or three R17 substituents as defined herein. Particularly useful R17 substituents include -(Alk2)pNH2 substituents as just generally and particularly discussed for R1.
Particularly useful compounds according to the invention include:
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-hydroxyethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[3-(2-hydroxyethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(1-imidazolyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)-3-fluorophenyl]-5-chloro-N-[4-(2-hydroxyethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(imidazol-1-yl)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(2-methylimidazol-1-yl)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(2-isopropylimidazol-1-yl)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-thiomorpholino)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(tertbutylamino)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(4-methylpiperazin-1-yl)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(4-ethylpiperazin-1-yl)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(3,5-dimethylpiperazin-1-yl)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(4-(pyrid-2-yl)piperazin-1-yl)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(pyrrolidin-1-yl)ethyl)phenyl]pyrimidine-2-amine;
4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(piperidin-1-yl)ethyl)phenyl]pyrimidine-2-amine;
(R)-4-[4-(1-Amino-1-methylethyl)phenyl]-5-chloro-N-[4-(2-(3-dimethylaminopyrrolidin-1-yl)ethyl)phenyl]pyrimidine-2-amine;
and the salts, solvates, hydrates and N-oxides thereof.
Compounds according to the invention are potent and selective inhibitors of KDR and/or FGFr4 kinases as demonstrated by differential inhibition of these enzymes when compared to inhibition of other protein kinases such as EGFr kinase, p56lck kinase, ZAP-70 kinase, protein kinase C, Csk kinase and p59fyn kinase. The ability of the compounds to act in this way may be simply determined by employing tests such as those described in the Examples hereinafter.
The compounds according to the invention are thus of particular use in the prophylaxis and treatment of diseases in which inappropriate KDR kinase action plays a role, for example in disease states associated with angiogenesis. The compounds are then of use for example in the prophylaxis and treatment of cancer, prosiasis, rheumatoid arthritis, Kaposi""s Sarcoma, ischemic heart disease, atherosclerosis and occular diseases, such as diabetic retinopathy, involving retinal vessl proliferation and the invention is to be understood to extend to such uses and to the use of a compound of formula (1) in the preparation of a medicament for the prophylaxis and teatment of such diseases.
For the prophylaxis or treatment of disease the compounds according to the invention may be administered as pharmaceutical compositions, and according to a further aspect of the invention we provide a pharmaceutical composition which comprises a compound of formula (1) together with one or more pharmaceutically acceptable carriers, excipients or diluents.
Pharmaceutical compositions according to the invention may take a form suitable for oral, buccal, parenteral, nasal, topical or rectal administration, or a form suitable for administration by inhalation or insufflation.
For oral administration, the pharmaceutical compositions may take the form of, for example, tablets, lozenges or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g. pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g. lactose, microcrystalline cellulose or calcium hydrogen phosphate); lubricants (e.g. magnesium stearate, talc or silica); disintegrants (e.g. potato starch or sodium glycollate); or wetting agents (e.g. sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents, emulsifying agents, non-aqueous vehicles and preservatives. The preparations may also contain buffer salts, flavouring, colouring and sweetening agents as appropriate.
Preparations for oral administration may be suitably formulated to give controlled release of the active compound.
For buccal administration the compositions may take the form of tablets or lozenges formulated in conventional manner.
The compounds for formula (1) may be formulated for parenteral administration by injection, including bolus injection or infusion or particle mediated injection. Formulations for injection may be presented in unit dosage form, e.g. in glass ampoule or multi dose containers, e.g. glass vials or a device containing a compressed gas such as helium for particle mediated administration. The compositions for bolus injection or infusion may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilising, preserving and/or dispersing agents. Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle, e.g. sterile pyrogen-free water, before use. For particle mediated administration the complex may be coated on particles such as microscopic gold particles.
In addition to the formulations described above, the compounds of formula (1) may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation or by intramuscular injection. Where desired, the compounds according to the invention may also be conjugated to a polymer, e.g. a naturally occuring polymer such as albumin, to prolong the half life of the compounds when in use. Such conjugates may be formulated and delivered as described above.
For nasal administration or administration by inhalation, the compounds for use according to the present invention are conveniently delivered in the form of an aerosol spray presentation for pressurised packs or a nebuliser, with the use of suitable propellant, e.g. dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas or mixture of gases.
The compositions may, if desired, be presented in a pack or dispenser device which may contain one or more unit dosage forms containing the active ingredient. The pack or dispensing device may be accompanied by instructions for administration.
The quantity of a compound of the invention required for the prophylaxis or treatment of a particular condition will vary depending on the compound chosen, and the condition of the patient to be treated. In general, however, daily dosages may range from around 100 ng/kg to 100 mg/kg e.g. around 0.01 mg/kg to 40 mg/kg body weight for oral or buccal administration, from around 10 ng/kg to 50 mg/kg body weight for parenteral administration and around 0.05 mg to around 1000 mg e.g. around 0.5 mg to around 1000 mg for nasal administration or administration by inhalation or insufflation.
The compounds of the invention may be prepared by a number of processes as generally described below and more specifically in the Examples hereinafter. In the following process description, the symbols R1, R2, R3, R4 and R5 when used in the text or formulae depicted are to be understood to represent those groups described above in relation to formula (1) unless otherwise indicated. In the reactions described below, it may be necessary to protect reactive functional groups, for example hydroxy, amino, thio or carboxy groups, where these are desired in the final product, to avoid their unwanted participation in the reactions. Conventional protecting groups may be used in accordance with standard practice [see, for example, Green, T. W. in xe2x80x9cProtective Groups in Organic Synthesisxe2x80x9d, John Wiley and Sons, 1991]. In some instances, deprotection may be the final step in the synthesis of a compound of formula (1) and the processes according to the invention described hereinafter are to be understood to extend to such removal of protecting groups.
Thus according to a further aspect of the invention, a compound of formula (1) may be prepared by reaction of a guanidine of formula (2): 
or a salt thereof
with an enaminone of formula (3):
R4COC(R5)CHN(R20)(R21)xe2x80x83xe2x80x83(3)
where R20 and R21, which may be the same or different is each a C1-6 Alkyl group.
The reaction may be performed in a solvent, for example a protic solvent such as an alcohol, e.g. ethanol, ethoxyethanol or propan-2-ol, optionally in the presence of a base e.g. an Alkali metal base, such as sodium hydroxide or potassium carbonate, at an elevated temperature, e.g. the reflux temperature.
Salts of the compounds of formula (2) include acid salts such as inorganic acid salts e.g. hydrochlorides or nitrates.
Intermediate guanidines of formula (2) may be prepared by reaction of the corresponding amine of formula (4): 
with cyanamide at an elevated temperature. The reaction may be performed in a solvent such as ethanol at an elevated temperature, e.g. up to the reflux temperature. Where it is desired to obtain a salt of a guanidine of formula (2) the reaction may be performed in the presence of a concentrated acid, e.g. hydrochloric or nitric acid.
The amines of formula (4) are either known compounds or may be obtained by conventional procedures, for example by hydrogenation of the corresponding nitro derivatives using for example hydrogen in the presence of a metal catalyst in a suitable solvent, for example as more particularly described in the interconversion reactions discussed below. The nitrobenzenes for this particular reaction are either known compounds or may be prepared using similar methods to those used for the preparation of the known compounds.
Intermediate enaminones of formula (3) are either known compounds or may be prepared by reaction of an acetyl derivative R4COCH2R5 with an acetal (R20)(R21)NCH(OR22)2 (where R22 is a C1-6Alkyl group such as a methyl or ethyl group) at an elevated temperature. The starting materials for this reaction are either known compounds or may be prepared by methods analogous to those used for the preparation of the known compounds.
In another process according to the invention, a compound of formula (1) may be prepared by displacement of a chlorine atom in a pyrimidine of formula (5): 
with an amine of formula (4)
The reaction may be performed at an elevated temperature, for example the reflux temperature, where necessary in the presence of a solvent, for example an alcohol, such as 2-ethoxyethanol or isopopanol, a cyclic ether, e.g. dioxane or a substituted amide such as dimethylformamide, optionally in the presence of a base, for example an organic amine such as pyridine.
Intermediate pyrimidines of formula (5) may be obtained by reaction of a corresponding pyrimidine of formula (6): 
with phosphorous oxychloride optionally in a solvent such as a substituted amide e.g. dimethylformamide at an elevated temperature, for example the reflux temperature.
Intermediates of formula (6) may be prepared from the corresponding amine of formula (7): 
with sodium nitrite in an aqueous acid,e.g. aqueous sulphuric acid at around ambient temperature.
Amines of formula (7) may be prepared by reaction of an enaminone of formula (3) with a guanidine salt, e.g. guanidine carbonate, as described above for the preparation of compounds of formula (1).
Compounds of formula (1) may also be prepared by interconversion of other compounds of formula (1) and it is to be understood that the invention extends to such interconversion processes. Thus, for example, standard substitution approaches employing for example Alkylation, arylation, heteroarylation, acylation, thioacylation, sulphonylation, formylation or coupling reactions may be used to add new substitutents to and/or extend existing substituents in compounds of formula (1). Alternatively existing substituents in compounds of formula (1) may be modified by for example oxidation, reduction or cleavage reactions to yield other compounds of formula (1).
The following describes in general terms a number of approaches which can be employed to modify existing phenyl and/or other aromatic of heteroaromatic groups in compounds of formula (1). It will be appreciated that each of these reactions will only be possible where an appropriate functional group exists in a compound of formula (1). Where desired, these reactions may also be performed on intermediates to compounds of formula (1).
Thus, for example Alkylation, arylation or heteroarylation of a compound of formula (1) may be achieved by reaction of the compound with a reagent Alk, L or ArL, where Alk is an Alkyl group and Ar is an aryl or heteroaryl group as defined above in relation to compounds of formula (1) and L is a leaving atom or group such as a halogen atom, e.g. a chlorine or bromine atom, or a sulphonyloxy group, e.g. an arylsulphonyloxy group such as a p-toluenesulphonyloxy group.
The Alkylation or arylation reaction may be carried out in the presence of a base, e.g. an inorganic base such as a carbonate, e.g. caesium or potassium carbonate, an Alkoxide, e.g. potassium t-butoxide, or a hydride, e.g. sodium hydride, in a dipolar aprotic solvent such as an amide, e.g. a substituted amide such as dimethylformamide or an ether, e.g. a cyclic ether such as tetrahydrofuran, at around 0xc2x0 C. to around 40xc2x0 C.
In a variation of this process the leaving group L may be alternatively part of the compound of formula (1) and the reaction performed with an appropriate nucleophilic reagent at an elevated temperature. Particular nucleophilic reagents include cyclic amines, such as piperazine. Where appropriate the reaction may be performed in a solvent such as an aprotic solvent, e.g. a substituted amide such as dimethylformamide.
In another general example of an interconversion process, a compound of formula (1) may be acylated or thioacylated. The reaction may be performed for example with an acyl halide or anhydride in the presence of a base, such as a tertiary amine e.g. triethylamine in a solvent such as a halogenated hydrocarbon, e.g. dichloromethane at for example ambient temperature, or by reaction with a thioester in an inert solvent such as tetrahydrofuran at a low temperature such as around 0xc2x0 C. The reaction is particularly suitable for use with compounds of formula (1) containing primary or secondary amino groups.
In a further general example of an interconversion process, a compound of formula (1) may be formylated, for example by reaction of the compound with a mixed anhydride HCOOCOCH3 or with a mixture of formic acid and acetic anhydride.
Compounds of formula (1) may be prepared in another general interconversion reaction by sulphonylation, for example by reaction of the compound with a reagent AlkS(O)2L, or ArS(O)2L in the presence of a base, for example an inorganic base such as sodium hydride in a solvent such as an amide, e.g. a substituted amide such as dimethylformamide at for example ambient temperature. The reaction may in particular be performed with compounds of formula (1) possessing a primary or secondary amino group.
In further examples of interconversion reactions according to the invention compounds of formula (1) may be prepared from other compounds of formula (1) by modification of existing functional groups in the latter.
Thus in one example, ester groups xe2x80x94CO2Alk1 in compounds of formula (1) may be converted to the corresponding acid [xe2x80x94CO2H] by acid- or base-catalysed hydrolysis or by catalytic hydrogenation depending on the nature of the group Alk1. Acid- or base-catalysed hydrolysis may be achieved for example by treatment with an organic or inorganic acid, e.g. trifluoroacetic acid in an aqueous solvent or a mineral acid such as hydrochloric acid in a solvent such as dioxan or an Alkali metal hydroxide, e.g. lithium hydroxide in an aqueous alcohol, e.g. aqueous methanol. Catalytic hydrogenation may be carried out using for example hydrogen in the presence of a metal catalyst, for example palladium on a support such as carbon in a solvent such as an ether, e.g. tetrahydrofuran or an alcohol, e.g. methanol.
In a second example, xe2x80x94OAlk [where Alk represents an Alkyl group such as a methyl group] groups in compounds of formula (1) may be cleaved to the corresponding alcohol xe2x80x94OH by reaction with boron tribromide in a solvent such as a halogenated hydrocarbon, e.g. dichloromethane at a low temperature, e.g. around xe2x88x9278xc2x0 C.
In another example, alcohol xe2x80x94OH groups in compounds of formula (1) may be converted to a corresponding xe2x80x94OAlk or xe2x80x94OAr group by coupling with a reagent AlkOH or ArOH in a solvent such as tetrahydrofuran in the presence of a phosphine, e.g. triphenylphosphine and an activator such as diethyl-, diisopropyl-, or dimethylazodicarboxylate.
Aminosulphonylamino [xe2x80x94NHSO2NH2] groups in compounds of formula (1) may be obtained, in another example, by reaction of a corresponding amine [xe2x80x94NH2] with sulphamide in the presence of an organic base such as pyridine at an elevated temperature, e.g. the reflux temperature.
In another example of an interconversion process secondary amine groups in compounds of formula (1) may be Alkylated using an alcohol, e.g. ethanol and catalytic hydrogenation, employing for example hydrogen in the presence of a metal catalyst such as palladium on a support such as carbon.
In a further example, amine [xe2x80x94NH2] groups in compounds of formula (1) may be obtained by hydrolysis from a corresponding imide by reaction with hydrazine in a solvent such as an alcohol, e.g. ethanol at ambient temperature. In an alternative, amine groups may also be generated by reduction of the corresponding nitrile, for example using a reducing agent such as a borohydride, e.g. sodium borohydride or cerium trichloride.
In another example, a nitro [xe2x80x94NO2] group may be reduced to an amine [xe2x80x94NH2], for example by catalytic hydrogenation as just described, or by chemical reduction using for example a metal, e.g. tin or iron, in the presence of an acid such as hydrochloric acid.
N-oxides of compounds of formula (1) may be prepared for example by oxidation of the corresponding nitrogen base using an oxidising agent such as hydrogen peroxide in the presence of an acid such as acetic acid, at an elevated temperature, for example around 70xc2x0 C. to 80xc2x0 C., or alternatively by reaction with a peracid such as peracetic acid in a solvent, e.g. dichloromethane, at ambient temperature.
Where salts of compounds of formula (1) are desired, these may be prepared by conventional means, for example by reaction of a compound of formula (1) with an appropriate acid or base in a suitable solvent or mixture of solvents, e.g. an organic solvent such as an ether, e.g. diethylether, or an alcohol, e.g. ethanol.
The following Examples illustrate the invention. In the Examples all 1Hnmr were run at 300 MHz unless specified otherwise. All temperatures are in xc2x0 C.
The following abbreviations are used:
THFxe2x80x94tetrahydrofuran;
DMSOxe2x80x94dimethylsulphoxide;
DMFxe2x80x94dimethylformamide;
TFAxe2x80x94trifluoroacetic acid;